Self-exciting alternate-current electric generator



(No Model.) 2 sheets-sheet 1f 0. A. MOSES. SELF EXCITING ALTERNATEOURRENT ELECTRIC GENERATOR. NO. 378 56. Patented Feb. 28, 1888.

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SELF EXCITING ALTERNATE CURRENT ELECTRIC GENERATOR.

N0.- 378A56. Patented Feb. 28, 1888.

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UNITED STATES PATENT OFFICE.

OTTO A. MOSES, OF NEW YORK, N. Y., ASSIGNOR TO THE WESTINGHOUSE ELECTRICCOMPANY, OF PITTSBURG, PENNSYLVANIA.

SELF-EXCITING ALTERNATE-CURRENT ELECTRICGENERATOR.

SPECIFICATION forming part of Letters Patent No. 378,456, dated February28, 1888.

Application filed March 28, 1887.

To all whom it may concern.-

Be it known that I, OTTO A. Mosns, a citizen of the United States,residing in New York, in the countyand State of New York,

5 have invented certain new and useful Improvements in Self-ExcitingAlternate-Ourrent Electric Generators, of which the following is aspecification.

The invention relates to the construction of alternate-current electricgenerators and to the organization of circuits therefor.

The object of the invention is to provide a generator which, whiledelivering alternate electric currents, shall be adapted to employ suchcurrents or a portion of the same for exciting its field-magnets. Theinvention consists, in general terms, in deriving alternate impulsesfrom the armature, transmitting a portion of each impulse of a givenpolarity through a set of magnetizing-coils applied to the field-magnetsand connectedi'n ashunt upon the main line or work-circuit, while thebalance of such impulses are transmitted directly to the main line, andin transmitting the impulses ofthe opposite polarity through a dividedcircuit, one division constituting a direct circuit to the main line,while the other circuit is through a second set of magnetizing-coilsoperating to assist the magnetizing effects of the firstnamed set. I

The invention also involves a'novel construction of the armature.

In the accompanying drawings, Figurel is a diagram illustrating ageneral organization of circuits adapted to carry out the invention.Figs. 2 and 3 illustrate modifications in the organization of thecircuits. Fig. & illustrates .the construction of the armature.

Referring to Fig. 1, A represents an armature, of any suitablecharacter, adapted to be moved in the field of force established byfield-magnets, the cores of which are represented at F F and F F. Thecores F and F have positions of alternate magnetic polarity. Thecurrents from the armature are delivered to a commutator, 0, consistingof two separate contact-rings, C O". The ring 0 is constructed withextensions or plates 0 c, separated from each other by non-conductingsurfaces 0 0 The distance of the plates Serial No. 232,627. (No model.)

from each other is preferably such that the reversion of the polarity ofthe currents will about take place when the brushes are leav ing themetallic parts of the commutator, and a conducting-plate will supplantin position a non-conducting plate for each alternation in the currentgenerated. Two collectingbrushes, K K, are applied to the rings 0 0respectively, and these are connected, respectively,with the mainlinesLandL,constitutiug the work-circuit. There are included in thiswork-circuit translating devices d d, of any suitable character-such,for instance, as incandcscent electric lamps, motors, Ste-the number ofwhich may be varied or is liable to be varied during the operation ofthe system.

For the purpose of maintaining the field of force for the armature thefield-magnets are wound with two sets of coils, ff and f The coils inthe arrangement shown in Fig. 1 are preferably constructed of fine wireand of comparatively high resistance, and the coils f f are applied tothe cores F, while the coils f f are applied to the cores F F The coilsmay be considered as all being Wound in the same direction.

The conducting plates or fingers 0 make alternate contact with twocontact-brushes, 7c is, respectively connected through conductors l and2 with one end of the series of coils f and f. The remaining ends ofthese series are connected with the main line L'. The brushes 7c and Z0are so arranged with reference to the contact-fingers that either one orthe other of the brushes will be in contact at any given time with oneof the conductingplates 0; but the two will not be in contact at thesame time for any relatively considerable length of time.

I hen the brush it is in contact with a finger c, a shunt-circuit aroundthe work-circuit will be established through the coils f. The currentwhich will traverse this circuit will depend upon the comparativeresistance of this circuit and the -work-circuit. As the re sistance ofthe latter decreases, the current through the coils f will diminish; butthe parts are so constructed that under a normal load the currenttraversing the coils will producea magnetic saturation on the part ofthe field-magnets. Therefore a considerable fluctuation may take placewithout materially changing the value of the field. 'When the armaturehas moved forward and placed the brush 7c against a non-conductingsurface 0 and the brush 76 against a conductingfinger c, then thecircuit through the coils f will be interrupted. The coils f will now bein circuit, but the current traversing these coils will be in theopposite direction from the preceding current. As the coils f and f arewound in the same direction, this will produce alternate poles at theinner ends of the alternate cores. The rapid succession of currents ofthe same polarity through each series of coils will secure a constantmagnetization of the cores. An adjustable resistance, t, is preferablyin sorted in the conductor 1, and a similar resistance, It", in theconductor 2 for controlling the liow of current therethrough. Anadditional resistance, 1, consisting of adjustable coils, may also beplaced between the conductors 1 and 2. The resistance r is inserted totake up the spark.

In Fig. 2 the coils f and f are represented as being connected inmultiple-arc circuit between the brush it and the line L and the brush kand the line L, respectively. In this instance the coils f 2 are ofcoarse wire and low resistance. The cores F will be excited by thecurrents traversing the shunt upon the translating devices (I d,- butthere will be two paths by which the currents may pass from the ring 0to the main line L-one directly by way of the brush K and the other byway of the brush conductor 2, including the coils f to the point 3, atwhich the latter coils are connected with the line L. The coils f are ofvery low resistance, and a proportionate current will traverse thesecoils. As the resistance of the work-circuit decreases by reason of morelampsd, for instance being included in multiple are, more current willtend to flow to line, and therefore the value of that traversing thecoils f will be increased. The lowering of the resistance of theworkcircuit, however, tends to decrease the current through the coils f,and the increase of current through the coils f will tend to regulatethe field of force and maintain the current constant.

In Fig. 3 the coils f are represented as connected in series, as in Fig.1, and the coils f as connected in multiple are, as in Fig. 2.

An armature well adapted to the purpose of this invention is illustratedin Fig. 4-. In this figure,a represents a shaft, of any suitablecharacter,upon which there is mounted a block of wood or other suitablenon-magnetic and nonconducting material, B, or it may be an insulatediron core or made of iron disks. This carries at one end a series ofradiating-plates, B B, and a similar series, B B, at the other end.These plates are secured to the block b in any convenient manner-as, forinstance, by having their inner ends,cl, bent parallel to the axis andcurved to fit the block or hub B. The plates are then screwed or boltedto the erases block, as shown at I) I). Aserics of plates or bars,11'1", of soft iron, are then placed between the plates B B Thus oneplate connects from one side of one plate 13 across to the opposite edgeof a plate I3 at the opposite end of the hub 13, it being understoodthat the plates B and B are placed in different radial lines. In thismanner a continuous me tallic circuit of soft iron is formed through thebars and end plates of the armature. Upon the shaft there are carriedthe two insulated collecting-rings C and G, which are respectivelyconnected with two of the plates B, which are opposite each other. Fromthese rings currents may be collected and employed in the manner abovedescribed,or in any wellknown manner.

When the armature is revolved within a suitable field, the passage ofthe bars E across the poles or the lines of force established by thefieldmagnets will cause currents of electricity to be generated in thebars.

It should be remarked that an armature constructed upon this principlemay be placed with its periphery very near to the poles of thefield-magnets, and therefore currents of comparatively-high potentialmay be developed.

I claim as my invention 1. The combination, with the armature of anelectric generator, of a series of field-magnets for the same andcircuit-controllingdevices connecting the alternate coils in circuitwith the armature alternately.

2. The combination,with the armature of an electric generator, offieldmagnet coils for the same arranged in two sets andcircuit'controlling devices connecting alternate sets of the coilsalternately in circuit.

3. The combination, with the armature of an electric generator, offield-magnet coils arranged in two sets and circuit-controlling devicestherefor connecting one of said sets of coils in circuit with thearmature during the production of currents of one polarity and the otherset during the production of currents of the opposite polarity.

4:. The combination, with the armature of an electric generator, offield-magnet coils arranged in two sets, the members of one of whichsets are between one terminal of the armature-coils and its otherterminal during the production of currents of a givenpolarity, anddevices for connecting the other coils in circuit during the productionof currents of the other polarity.

5. The combination, with the armature of an electric generator, offield-magnet coils arranged in two sets, the members of one of whichsets are between one terminal of the armature-coils and its otherterminal during the production-of currents of agiven polarity, anddevices for connecting the other coils in circuit with the armature inmultiple arc during the production of currents of the other polarity.

6. The combination, with the armature of an electric generator, of twosets of alternatelyarranged field-magnet cores and their respectivecoils, the coils of each set'being arranged in multiple arc with eachother, collectingrings connected with the respective terminals of thearmature-coils, contact-brushes respectively making alternate contactwith one of said rings and respectively connected with one terminal ofsaid sets of coils, and conductors respectively connecting the remainingterminals of said sets of coils with the contact-rings.

7. The hereinbefore-described method of maintaining the field of forceof an alternate current electric generator, which consists inestablishing by successive currents of one p0- larity lines of magneticforce at certain points and by currents of the other polarity lines offorce at other points.

8. The hereinbefore-described method of maintaining the field of forceof an alternate- 20 current electric generator, which consists intransniittingsuccessive currents of one polarity through one circuit andsuccessive currents of the other polarity through another circuit, andin causing such currents by their com- 25 bined action to induce suchfield of force.

In testimony whereof I have hereunto subscribed my name this 11th day ofMarch, A.

orro A. Moses.

Witnesses:

DANL. W. EDGEOOMB, CHARLES A. TERRY.

